Spark-coil.



U. H. THORDARSON.

SPARK COIL.

APPLICATION FILED NOV.17,190B.

952,692. Patented Mar. 22, 1910.

ldjz'zeziisfs Z Inventor PATENT OFFICE.

CHESTER H. THORDARSON, OF CHICAGO, ILLINOIS.

SPARK-COIL.

Specification of Letters Patent.

.laftontod Mar. I910.

Application filed November 17, 1908. Serial No. 463,054.

To all whom it may concern:

Be it known that I, Cuus'rnn H. 'luonmnson, a citizen of the UnitedStates, residing at Chicago, in the county of (look, State of Illinois,have made a certain new and useful Invention in Spark-Coils, of whichthe following is a specification.

This invention relate." to spark coils of the character required for usein connection with ignition systems of explosive engines, although sparkcoils emlmdying my inven tion are equally well adapted for use in otherrelations and for other purposes for which such coils are required ordevised.

The object of the invention is to, provide a construction of spark coilsof the character referred to which is simple, inexpensive, strong,durable "and etlicicnt, and which is not affected by moisture. I

Other objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination,location and rel ative arran emcnt of parts, all as will be more fullyiercinatter set forth, as shown in the accompanying draw'nw, and finallypointed out in the appended c aims.

Referring to the accompanying drawing, and to the. various views andreference signs appearing thereon Figure 1 is a view in transversesection of a construction of spark coil embodying my invention. Fig. 2is a longitudinal section of-the same.

In the drawing, reference sign A, designates a base of cast iron, and B,an inelosing cup-shaped easing of the samematerial, the base and easingbeing fittedand secured together to inclose the coil I), and its core F,

said coil and core being supported longitndmallybetween the base and theend of the casing, one end of the core resting on the interior surfaceof the base, and the inner surface of the casing end bearing a ailistthe other end of the core. If desired, and preferably, a sheet ofinsulating materiabM, may be interposed between the end surfocc of thecore and the surface of the base A, against which the core bears therebyfori'ning and maintaining a se oration of the end surface of the coreand t e adjacent Surface of the base, to constitute agap at this pointin the magnetic circuit. The coil D, is preferably of heavy cop or wireand is wound upon the core F, witii an inter os'ed insulat in Sloeve'brmaterial E,there tWeenJ-Thc tan 5 of the coil terminate at binding postsK, which project through openings in the casing, being insulatedtherefrom by means of the sleeve and washers indicated at H. The ends ofthe coil are sccured'in eflicicnt electric contact withthc binding postsK, by means of the plates or washers (l, and, out side the casing, thebinding posts are equipped with the usual binding nuts and washers J, IAfor circuit Wire cornicctions.

If desired, and in order to secure durability of the device and also toprotect the coil against moisture, the space t, between the coil andeasing may be filled with insulating compound.

The core F is made up of plates or lami nations of iron, and these maybe arranged in any suitable or convenient relation with respect to eachother for the wire or conductor coils to be'wound therearound into 0ylindrical form.

It has been demonstrated that except as to its permeability, cast ironbehaves very much like laminated iron with respect to the rapidity withwhich it demagnetizes. This is due to its porosity and high electricalresistance. In carr ing out my invention, therefore, I emp 0y cast ironfor the base and casing, and I make these parts sufficiently heavy tocarry the magnetism of the laminated core to form very nearly a closedmagnetic circuit. In fact this magnetic circuit is closed except for thegap formed by the sheet M interposed between the base casting and thecore, and since the mass of cast iron composing the base and easingsurrounds and incloses the coil and its core I am enabled to secure thedesired results and to produce a strong durable device having greatcfiieicnc as a spark coil, and which can be cheapy manufactured, andwhich is protected from moisture.

It will be observed that the laminations composing the core are notsymmetrically arrangedhwithin the coil. This is due to the fact that thelaminations, in the Blblf'tb lar construction shown, are in the orm of'rflat plates of ual rectangular size which are inclosed wit in acircular coil. My invention, however, in its broadest scope as definedin the claims, is not to be limited or restricted in this respect.

It will also be seen that by employing heavy cop or wire for magnet coilwindings I am enabled to secure a high impedance with low resistance inthe magnetizing coil, thereby rapidly accumulating and storing encrgv inthe circuit when the circuit is (JOSH. and also rapidly returning suchenergy to the circuit when it is opened, and hence enabling the releasedenergy to augment the spark making the latter of greater length and ofgreater degree of heat than is possible from the battery or currentsource energ alone, and hence very greatly increasing t e efiiciency ofthe spark discharge.

Having now set forth the object and nature of my invention, and aconstruction ernbodying the principles thereof, what I claim as new anduseful, and of my own invention,

and desire to secure by Letters Patent is,'-

1. In a spark coil, a cast iron base, a cast iron casing supportedthereon, said casing having a permanently closed integral end, alaminated core independent of the casing and its base and arrangedWithin the casin and having its ends presented toward and held betweenthe base and closed end, respectively, of the casing thereby forming airgaps between the ends of the core and the base and closed endrespectively of the cars ing, a single he'avy low resistance coilsurrounding the laminated core and inclosed within the casing, andcircuit terminals for said coil, said terminals extending through to theoutside of the casing. 2. In a spark coil, a cast iron base, an invertedcup shaped cast iron casing supported thereon, a laminated coreindependent of the base andcasing, but contacting at one end with theinner end surface of the inverted cup-shaped casing and resting at itsother end u on said base, an insulating sheet interpose between the coreand base a heavy low resistance conductor coil surroundin said core, andcircuit terminals for sai coil, said terminals extending throu h saidcasm -3. n a spark CO1 a cast iron base, an 111-- verted cup-shaped castiron casin supported thereon, a laminated core in ependent of the baseand easing, but contacting at one end with the inner surface of, theinverted cup-shaped casing, and resting at its other and upon .saidbase, an insulating sheet intei osed between said core and base, aninsulating sleeve inclosing said core, a heavy low resistance conductorcoil surrounding said sleeve, and circuit terminals for said coil, saidterminals extending through the Wallof said casing.

In testimony whereof I have hereunto set my hand in the presence of thesubscribing witnesses, on this 11th day of November CHESTER H.THORDARSON.

Witnesses SYLvANos E. LAMBERT, HENRY L. HANLEY.

